Gas-check for projectiles.



No. 648,243. Patented Apr. 24, I900.

A. T. DAWSON, G. T. BUCKHAM &. L. SILVEBMAN.

GAS CHECK. FOR PROJEGTILES.

(Application filed Dec. 18, 1899.) (No Model.)

ven ars ilwrrnn Era-ions ATENT f rries.

ARTHUR 'rREvoR DAWSON, GEORGE '1. RUoKnAM, AND Louis SILVERMAN, .oE LONDON, ENGLAND, ASSIGNORS TO THE vIoKERs, sows rt MAXIM, IMITED, oE SHEFFIELD, ENGLAND.

yeAs-c-H ECK' FOR PROJECl'lLE'S.

$PECIFICATION forming part of Letters Patent No. 68,243, dated April 24, 1900.

Application filed Decemher1 8,189 9. Serial No. 740,778. (No model-l T ZZ wh m m y c ncern: The flanges are preferably of such diame- Beitknown that we,ARTHURTREv0RDAW- ter that when the p'rojectilcis pushed home SON, GEORGE THOMAS BUOKHAM, and LOUIS the rearmost flange oomes' fi1'st in contact '5 5 SILVERMAN,citizensof England, residing'at28 with the interior surface of the chamber and 5 Victoria street, Westminster, London, Engis bent somewhat back before the flange in land, have invented a certain new and usefront of it meets the surface of the chamber. ful Improvement in Gas-Checks for Project- The rear flange is preferably madein thefirst iles, (forwhichwe-have applied forapatentin" instance with an inclination rearward. In V GreatBritain, dated April 26, 1899,No.8,758,)- this manner thereis obtained a perfect pis- 1-10 of which the following is a specification. ;j ton litot' theflanges and the plastic material Our invention relates to the construction between them when the projectile is pushed of projectiles for heavy guns with gas-checks by the -rammer, and. when the charge is fired so arranged as to prevent or diminish the the rear flange is caused to fit still more 5 erosive effect produced on the bore by the ex .jtightiy by the'pressure of the explosion-gases. x5 plosion of heavy. charges, this erosive efiect {The packing material placed in the grooves being principally due to the passage of-the' between the flanges consists, preferably, of highly-heated explosion-gases between the asbestos saturated with wax, plumbago, or projectile and theinterior surface of the here. other suitable lubricant. '70 We construct the gas-check and provide it. The coveringband It may be dispensed 2o with-plastic'paeking of ainbricating characwith"; but it isuse'ful' for protectingthepackter, so that it fits the bore like a piston, preing and flanges during the handling or storventing passage of the hot gases, and also lu- 7 ing ofthe projectiles. bricates the bore. 1 Although we have shown the extension e The accompanying drawing is a longitudias made intone piece with the driving-band 2 5 nal section of the rear part of a shell prod, it might obviously be a separate ring, put' vided with a gas-check according to our in on iii/the same way as the driving-band. vention. The gas-check is obviously applicable to a is part of the gun, showing the profile of solid shot as well as shell. I the internal surface of the bore 1) and the Having thus described thenature of this 30 charge-chamber o. The-projectile phas on invention and the best-means we know of its rear part the driving-band d, which is of carrying the same into practical effect, we the usual kind for taking the riding, but acclaim- 4 I cording to our invention is madewith a ra- The herein-described gas-check for project-l dially-fixed rearward extension 6, from which iles consisting of a ring arranged on'the pro- 5 project several flanges f, extending; beyond jectile behind the driving band, radially the circumferential line of the interior wall fixed throughout its" length andprovided of the bore of the gun and having their inwith a plurality of projecting flexible flanges terva-ls charged with lubricating material g, extending beyond-the circumferential line of protected by a thin sheetmetal coveringthe interior wall of the bore of the gun and 40 hand h. The flanges f are comparatively containing in the intervening spaces plastic thin, so that while they give sufficient snppacking of lubricating character, substanport to the packing it requires comparatively tially as and for the purposeset forth. little force to make them take the rifling, and In testimony whereof we have hereunto set 9 5' any one can fold backward when it meets our hands in'presence of two-subscribingwitwith excessive resistance, so that .none of nesses. them is likely to be torn ofi during the pas.-

sage of the projectile alongthe bore. Therefore the flanges f are flexible, and it will be LOUIS SHXIERMAN seen that when the rear flange is actednp'on' so by the powder-gases on firing it is forced for- Witnesses:

ward and compresses the packing in front of WILLIAM WALKER SHARPE,

it, forcing the latter outward. HENRY KING. 

